it all stems from the internal accounting rules set up by a certain government years ago, if one department works in a building 'owned' by another department then you have to have an over paid bunch of accountants to prove that the council paid proper rent to itself and wasn't treating itself favourably by renting its own buildings to itself for nothing.

Strangley the same government didn't apply the same rules regarding rent backs to private businesses using it is a tax fiddle.

Local government accountancy rules were ridiculous for many years, but towards the latter end of my time there... I left in 1998 ... they became much more flexible. I'd have thought that the true savings on closing the library come on staffing, heating, transport, archiving etc. The rent argument may be just a filibuster.